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COBOL Data Encryption

Data encryption protects sensitive information by converting it into secure formats that cannot be read without proper decryption keys. Learn to implement data security, encryption algorithms, and secure data handling in COBOL programs.

Basic Data Encryption Concepts

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       WORKING-STORAGE SECTION.
       01 ENCRYPTION-DATA.
           05 PLAINTEXT-DATA PIC X(50).
           05 ENCRYPTED-DATA PIC X(50).
           05 DECRYPTED-DATA PIC X(50).
           05 ENCRYPTION-KEY PIC X(16).
           05 ENCRYPTION-ALGORITHM PIC X(10) VALUE 'AES-256'.
       
       PROCEDURE DIVISION.
       MOVE 'SENSITIVE CUSTOMER DATA' TO PLAINTEXT-DATA
       PERFORM ENCRYPT-DATA
       PERFORM DECRYPT-DATA
       DISPLAY 'Original: ' PLAINTEXT-DATA
       DISPLAY 'Encrypted: ' ENCRYPTED-DATA
       DISPLAY 'Decrypted: ' DECRYPTED-DATA.

Understand encryption concepts: plaintext (original data), ciphertext (encrypted data), encryption keys, and algorithms. Implement encryption and decryption procedures to protect sensitive data from unauthorized access.

Data Classification and Protection

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       WORKING-STORAGE SECTION.
       01 DATA-CLASSIFICATION.
           05 DATA-TYPE PIC X.
               88 PUBLIC-DATA VALUE 'P'.
               88 INTERNAL-DATA VALUE 'I'.
               88 CONFIDENTIAL-DATA VALUE 'C'.
               88 SECRET-DATA VALUE 'S'.
           05 PROTECTION-LEVEL PIC X.
               88 NO-PROTECTION VALUE 'N'.
               88 BASIC-PROTECTION VALUE 'B'.
               88 HIGH-PROTECTION VALUE 'H'.
               88 MAXIMUM-PROTECTION VALUE 'M'.
       
       PROCEDURE DIVISION.
       PERFORM CLASSIFY-DATA USING CUSTOMER-SSN
       IF SECRET-DATA
           PERFORM APPLY-MAXIMUM-PROTECTION
       ELSE IF CONFIDENTIAL-DATA
           PERFORM APPLY-HIGH-PROTECTION
       END-IF.

Classify data based on sensitivity levels and apply appropriate protection measures. Use data classification to determine encryption requirements and access controls for different types of information.

Encryption Key Management

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       WORKING-STORAGE SECTION.
       01 KEY-MANAGEMENT.
           05 MASTER-KEY PIC X(32).
           05 DATA-KEY PIC X(32).
           05 KEY-VERSION PIC 9(4).
           05 KEY-EXPIRY-DATE PIC 9(8).
           05 KEY-STATUS PIC X.
               88 KEY-ACTIVE VALUE 'A'.
               88 KEY-EXPIRED VALUE 'E'.
               88 KEY-REVOKED VALUE 'R'.
       
       PROCEDURE DIVISION.
       PERFORM GENERATE-ENCRYPTION-KEY
       PERFORM VALIDATE-KEY-STATUS
       IF KEY-EXPIRED
           PERFORM ROTATE-ENCRYPTION-KEY
       END-IF.

Implement secure key management practices including key generation, validation, rotation, and secure storage. Use master keys to encrypt data keys and implement key versioning for security updates.

Data Encryption Procedures

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       ENCRYPT-SENSITIVE-DATA USING INPUT-DATA OUTPUT-DATA.
           *> Validate input data
           IF FUNCTION LENGTH(FUNCTION TRIM(INPUT-DATA)) = 0
               DISPLAY 'Error: No data to encrypt'
               EXIT PARAGRAPH
           END-IF.
           
           *> Generate encryption key if needed
           IF ENCRYPTION-KEY = SPACES
               PERFORM GENERATE-ENCRYPTION-KEY
           END-IF.
           
           *> Apply encryption algorithm
           PERFORM APPLY-ENCRYPTION USING INPUT-DATA ENCRYPTION-KEY
           MOVE ENCRYPTED-RESULT TO OUTPUT-DATA
           
           *> Log encryption operation
           PERFORM LOG-ENCRYPTION-OPERATION USING 'ENCRYPT' INPUT-DATA.
       
       DECRYPT-SENSITIVE-DATA USING INPUT-DATA OUTPUT-DATA.
           *> Validate encrypted data
           IF INPUT-DATA = SPACES
               DISPLAY 'Error: No data to decrypt'
               EXIT PARAGRAPH
           END-IF.
           
           *> Apply decryption algorithm
           PERFORM APPLY-DECRYPTION USING INPUT-DATA ENCRYPTION-KEY
           MOVE DECRYPTED-RESULT TO OUTPUT-DATA
           
           *> Log decryption operation
           PERFORM LOG-ENCRYPTION-OPERATION USING 'DECRYPT' OUTPUT-DATA.

Create comprehensive encryption and decryption procedures with validation, error handling, and logging. Ensure proper key management and secure handling of sensitive data throughout the encryption process.

Data Integrity Verification

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       WORKING-STORAGE SECTION.
       01 INTEGRITY-CHECK.
           05 ORIGINAL-HASH PIC X(32).
           05 CALCULATED-HASH PIC X(32).
           05 INTEGRITY-STATUS PIC X.
               88 DATA-INTACT VALUE 'Y'.
               88 DATA-CORRUPTED VALUE 'N'.
       
       PROCEDURE DIVISION.
       PERFORM CALCULATE-DATA-HASH USING ORIGINAL-DATA
       MOVE HASH-RESULT TO ORIGINAL-HASH
       
       PERFORM CALCULATE-DATA-HASH USING RECEIVED-DATA
       MOVE HASH-RESULT TO CALCULATED-HASH
       
       IF ORIGINAL-HASH = CALCULATED-HASH
           MOVE 'Y' TO INTEGRITY-STATUS
           DISPLAY 'Data integrity verified'
       ELSE
           MOVE 'N' TO INTEGRITY-STATUS
           DISPLAY 'Error: Data integrity check failed'
       END-IF.

Implement data integrity verification using hash functions to detect data corruption or tampering. Calculate hashes for original and received data and compare them to ensure data integrity.

Secure Data Storage

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       WORKING-STORAGE SECTION.
       01 SECURE-STORAGE.
           05 STORAGE-TYPE PIC X.
               88 ENCRYPTED-STORAGE VALUE 'E'.
               88 PLAINTEXT-STORAGE VALUE 'P'.
           05 STORAGE-LOCATION PIC X(50).
           05 ACCESS-CONTROLS.
               10 READ-ACCESS PIC X.
               10 WRITE-ACCESS PIC X.
               10 DELETE-ACCESS PIC X.
       
       PROCEDURE DIVISION.
       PERFORM DETERMINE-STORAGE-TYPE USING DATA-CLASSIFICATION
       IF SECRET-DATA
           MOVE 'E' TO STORAGE-TYPE
           PERFORM SETUP-ENCRYPTED-STORAGE
       ELSE
           MOVE 'P' TO STORAGE-TYPE
           PERFORM SETUP-PLAINTEXT-STORAGE
       END-IF.

Implement secure data storage based on data classification. Use encrypted storage for sensitive data and implement appropriate access controls for different storage types and data sensitivity levels.

Encryption Error Handling

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       HANDLE-ENCRYPTION-ERROR USING ERROR-TYPE ERROR-MESSAGE.
           ADD 1 TO ENCRYPTION-ERROR-COUNT
           DISPLAY 'Encryption Error: ' ERROR-TYPE ' - ' ERROR-MESSAGE
           
           *> Log security error
           MOVE FUNCTION CURRENT-DATE TO ERROR-TIMESTAMP
           WRITE SECURITY-LOG-RECORD
           
           *> Set appropriate return code
           EVALUATE ERROR-TYPE
               WHEN 'KEY-INVALID'
                   MOVE 16 TO RETURN-CODE
               WHEN 'ALGORITHM-ERROR'
                   MOVE 20 TO RETURN-CODE
               WHEN 'DATA-CORRUPTION'
                   MOVE 24 TO RETURN-CODE
               WHEN OTHER
                   MOVE 28 TO RETURN-CODE
           END-EVALUATE
           
           *> Notify security team if critical error
           IF ERROR-TYPE = 'SECURITY-BREACH'
               PERFORM NOTIFY-SECURITY-TEAM
           END-IF.

Implement comprehensive error handling for encryption operations with specific error codes, security logging, and notification procedures. Handle different types of encryption errors appropriately.

Encryption Performance Considerations

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       WORKING-STORAGE SECTION.
       01 PERFORMANCE-METRICS.
           05 ENCRYPTION-TIME PIC 9(6).
           05 DECRYPTION-TIME PIC 9(6).
           05 DATA-SIZE PIC 9(8).
           05 PERFORMANCE-THRESHOLD PIC 9(6) VALUE 1000.
       
       PROCEDURE DIVISION.
       PERFORM MEASURE-ENCRYPTION-PERFORMANCE
       IF ENCRYPTION-TIME > PERFORMANCE-THRESHOLD
           DISPLAY 'Warning: Encryption performance below threshold'
           PERFORM OPTIMIZE-ENCRYPTION-PROCESS
       END-IF.
       
       *> Use appropriate encryption for data size
       IF DATA-SIZE > 1000000
           PERFORM USE-BATCH-ENCRYPTION
       ELSE
           PERFORM USE-STREAM-ENCRYPTION
       END-IF.

Monitor encryption performance and optimize for different data sizes and processing requirements. Use appropriate encryption methods for batch vs. stream processing and implement performance monitoring.

Data Encapsulation

Data hiding and access control

Security

COBOL security practices